Booster seats: What parents need to know

All booster seats face forward, so most are not good for children younger than 3.

Seats should be used with lap and shoulder belt, unless they have a harness. Belt should not be across the stomach, neck or other soft tissue areas.

Shoulder belt should lie on a child's collarbone and shoulder, with lap belt across hips or high on thighs..

Children should ride in a booster seat until they are at least 4 feet, 9 inches tall and 80 pounds. Before leaving the booster, their legs should be long enough for knees to bend at the seat edge when seated with their bottom touching the vehicle seat's back.

The National Highway Traffic Safety Administration has "ease of use" ratings for all car seats. Go to safercar.gov and click on "child safety." Seat recalls also posted here. Or call 888-327-4236.

Always send in product registration cards for new car seats so you can be contacted if there is a recall. This information cannot be used for marketing.

All car seats have expiration dates, usually embossed on the base. Seats usually should not be used longer than six years.

Always discard any seat that has been in a crash and do not buy second-hand seats at thrift stores or online.

Three main types

Backless booster seat

Almost like sitting on a cushioned plastic phone book. Uses vehicle's seat belts.

Pros: Inexpensive. Little installation; easy to move. Does not show from outside car, if child is worried about being teased by peers.

Cons: Only for cars with good headrests. Offers no head, neck support. Best for older children. Make sure shoulder belt adjuster, usually a plastic clip or a cord, is easy to use and gives a good fit. Children easily can move shoulder belt behind their back, which is dangerous.

High-back booster seat

More chair-like, with side wings and back. Uses vehicle's seat belts.

Pros: Fairly inexpensive. Some have backs that extend as child grows. Gives good neck and head support. Wings give good sleep support.

Cons: Many will not fit a child above 40 pounds. Some have tight head supports.

Combination booster seats

More like a traditional car seat. Uses a five-point harness rather than seat belts, which can be removed as child grows.

Pros: Harness is safer than seat belt. Better for younger-aged child transitioning to a booster. Can accommodate wide range of sizes and ages, extending seat's use life.

Cons: Not good for very young children, although weight minimums can be as low as 20 pounds, because seats face forward. Car headrests can interfere with placement of some high-back models.